Mediatags – undefined function error

I’m using mediatags on a series of images with the WordPress Media Tags plugin. I use the following shortcode:

[wp-flowplus mediatag=mytagname]

And get the following error:

Fatal error: Call to undefined function get_attachments_by_media_tags() in /::path_to_my_install_dir::/wp-content/plugins/wp-imageflow2/wp-imageflow2.php on line 332

Any idea what’s going on?

Scott

https://ww.wp.xz.cn/plugins/wp-imageflow2/